Effects of Different Support Surfaces on the Properties Skin After Loading

Not Applicable

Completed

Conditions: Pressure Ulcers

Interventions: Other: Gel mattress
Other: Alternating low pressure mattress with air loss function
Other: Basic foam

Registration Number: NCT02930590

Lead Sponsor: Charite University, Berlin, Germany

Brief Summary: Pressure ulcers are severe injuries and wounds causing a substantial burden on patients, caregivers, and on healthcare systems worldwide. There is common agreement, that effective pressure ulcer prevention is of crucial importance to maintain skin and tissue integrity in individuals at risk. Besides risk assessment and repositioning the use of special pressure ulcer preventive support surfaces are the key interventions in pressure ulcer prevention. Pressure ulcer preventive support surface modify the degree of skin and tissue deformation and/or skin temperature and moisture. Therefore, an association between the type and working mechanism of a pressure ulcer support surface and skin function after loading is highly likely. Furthermore, such a relationship may be used to characterize and/or to quantify the performance pressure ulcer support surfaces in terms of skin protection. The overall aim of this explorative study is to measure skin responses of the two most common pressure ulcer predilection sites (heel, sacral skin) after two hours loading on three different support surfaces and the sternal skin (control area).

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 15

Inclusion Criteria

Healthy, female volunteers
60 to 80 years
Body Mass Index between 18.5 and 29.9 kg/m2
Non-Smoker of at least one year
Absence of skin diseases or scars in the skin areas of interest
Ability to move independently and to maintain supine and prone positions
Able to give written informed consent
No use of cosmetic products or topical applied drugs on the study areas at least 12 hours before measurement
Skin phototype I to III according to Fitzpatrick classification
Willing and able to fulfil the study requirements

Exclusion Criteria

Disability to maintain in supine or prone position
Acute diseases
Acute or chronic diseases with increased or decreased body temperature (≤ 35°C or ≥ 38,5°C, measured in the ear)
History or establishment of Diabetes or pre-diabetes, cardiac or renal insufficiency, atopic dermatitis, psoriasis, chronic obstructive pulmonary disease (COPD)
Acute or chronic wounds in the skin areas of interest
Any skin affection which may interfere with the study assessment, e.g. tattoo, psoriasis or scar on the investigational sites
Participation in another clinical study 4 weeks before inclusion visit
Current participation in any other clinical study

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Reactive support surface	Gel mattress	Gel mattress (IsoGel, stryker, USA)
Low Pressure mattress	Alternating low pressure mattress with air loss function	Alternating Low Pressure mattress with low air loss function (IsoAir, stryker, USA)
Standard mattress	Basic foam	basic foam

Primary Outcome Measures

Name	Time	Method
Transepidermal Water Loss (TEWL) in g/m2/h on Sacrum, at Baseline	at baseline	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Sacrum, 20 Min After Off-loading	20 min after off-loading	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Sacrum, After Two Hours Loading	after two hours loading	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Heel, at Baseline	at baseline	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Heel, After Two Hours Loading	after two hours loading	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Heel, 20 Min After Off-loading	20 min after off-loading	TEWL was measured using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).

Secondary Outcome Measures

Name	Time	Method
Erythema Index in Arbitrary Units at the Sacrum, at Baseline	at baseline	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Erythema Index in Arbitrary Units at the Heels, at Baseline	at baseline	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Erythema Index in Arbitrary Units at the Heels, After Two Hours Loading	after two hours loading	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Skin Surface Temperature in °C Per Skin Area at the Sacrum, at Baseline	at baseline	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Skin Surface Temperature in °C Per Skin Area at the Sacrum, 20 Minutes After Off-loading	20 minutes after off-loading	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Skin Surface Temperature in °C Per Skin Area at the Heel, 20 Minutes After Off-loading	20 minutes after off-loading	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Erythema Index in Arbitrary Units at the Sacrum, After Two Hours Loading	after two hours loading	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Heels, After Two Hours Loading	after two hours loading	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Heels, 20min Off-loading	20 min after off-loading	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Skin Surface Mean Roughness (Rz) in μm at the Heels, 20min Off-loading	20 min after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Heels, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Sacrum, at Baseline	Baseline	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Sternum (Control- Area), at Baseline	Baseline	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Skin Surface Temperature in °C Per Skin Area at the Sacrum, After Two Hours	after two hours	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Sacrum, 20 Min Off-loading	20 min after off-loading	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU).Lower values represent reduced skin hydration in the upper skin layer.
Skin Surface Mean Roughness (Rz) in μm at the Sacrum, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Maximum Roughness (Rmax) in µm at the Sacrum, 20 Min Off-loading	20 minutes after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Elastic Recovery (Ur/Uf) at the Heel, After Two Hours Loading	after two hours loading	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Surface Temperature in °C Per Skin Area at the Heel, at Baseline	at baseline	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Skin Surface Temperature in °C Per Skin Area at the Heel, After Two Hours Loading	after two hours loading	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Erythema Index in Arbitrary Units at the Sacrum, 20 Min After Off-loading	20 min after off-loading	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Sacrum, After Two Hours Loading	after two hours loading	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Heels, at Baseline	Baseline	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU).Lower values represent reduced skin hydration in the upper skin layer.
Skin Surface Mean Roughness (Rz) in μm at the Sacrum, 20 Min After Off-loading	20 min after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Maximum Roughness (Rmax) in µm at the Sacrum, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Surface Mean Roughness (Rz) in μm at the Heels, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Heels, 20 Min After Off-loading	20 min after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Maximum Roughness (Rmax) in µm at the Heel, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Surface Maximum Roughness (Rmax) in µm at the Heel, 20 Min After Off-loading	20 minutes after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Extensibility (Uf) in mm at the Sacrum, 20 Minutes After Off-loading	20 minutes after off-loading	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the Skin in mm (Uf, mm).
Erythema Index in Arbitrary Units at the Heels, 20 Min After Off-loading	20 min after off-loading	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Sacrum, at Baseline	at baseline	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Skin Surface Mean Roughness (Rz) in μm at the Sacrum, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Sacrum, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Sacrum, After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Sacrum, 20 Min Off-loading	20 min after off-loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Maximum Roughness (Rmax) in µm at the Sacrum, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Surface Mean Roughness (Rz) in μm at the Heel, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Heels, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Maximum Roughness (Rmax) in µm at the Heel, at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Extensibility (Uf) in mm at the Sacrum, at Baseline	Baseline	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted with a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Skin Extensibility (Uf) in mm at the Sacrum, After Two Hours Loading	after two hours loading	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm(Uf, mm).
Skin Extensibility (Uf) in mm at the Heel, at Baseline	Baseline	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Skin Extensibility (Uf) in mm at the Heel, After Two Hours Loading	after two hours loading	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Skin Elastic Function (Ur/Ue) at the Sacrum, After Two Hours Loading	after two hours loading	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Epidermal Thickness in μm (Metric) by Image Processing and Measurement at the Sternum (Control- Area)	after two hours loading	Skin thickness was measured in μm (Metric) by Image Processing using Optical Coherence Tomography, OCT (Thorlabs, Lübeck, Germany).
Transepidermal Water Loss (TEWL) in g/m2/h on Sternum (Control- Area), at Baseline	at baseline	TEWL was measured on sternum (control- area) using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany)
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Elastic Recovery (Ur/Uf) at the Sacrum, at Baseline	Baseline	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Elastic Recovery (Ur/Uf) at the Heel, 20 Minutes After Off-loading	20 minutes after off-loading	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Elastic Function (Ur/Ue) at the Heel, at Baseline	Baseline	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Elastic Function (Ur/Ue) at the Heel, After Two Hours Loading	after two hours loading	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Sacrum, 20 Minutes After Off-loading	20 minutes after off-loading	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Heel, After Two Hours Loading	after two hours loading	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Transepidermal Water Loss (TEWL) in g/m2/h on Sternum (Control- Area), After Two Hours Loading	after two hours loading	TEWL was measured on sternum (control- area) using the Tewameter TM300 (Courage \& Khazaka, Cologne, Germany).
Skin Surface Temperature in °C Per Skin Area at the Sternum (Control- Area), at Baseline	Baseline	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Skin Extensibility (Uf) in mm at the Heel, 20 Minutes After Off-loading	20 minutes after off-loading	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Elastic Recovery (Ur/Uf) at the Sacrum, After Two Hours Loading	after two hours loading	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Elastic Recovery (Ur/Uf) at the Sacrum, 20 Minutes After Off-loading	20 minutes after off-loading	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Epidermal Thickness in μm (Metric) by Image Processing and Measurement at the Heel	after two hours loading	Skin thickness was measured in μm (Metric) by Image Processing using Optical Coherence Tomography, OCT (Thorlabs, Lübeck, Germany).
Elastic Recovery (Ur/Uf) at the Heel, at Baseline	Baseline	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Elastic Function (Ur/Ue) at the Sacrum, at Baseline	Baseline	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Elastic Function (Ur/Ue) at the Sacrum, 20 Minutes After Off-loading	20 minutes after off-loading	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Skin Elastic Function (Ur/Ue) at the Heel, 20 Minutes After Off-loading	20 minutes after off-loading	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Heel, at Baseline	Baseline	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Epidermal Thickness in μm (Metric) by Image Processing and Measurement at the Sacrum	after two hours loading	Skin thickness was measured in μm (Metric) by Image Processing using Optical Coherence Tomography, OCT (Thorlabs, Lübeck, Germany).
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Sacrum, After Two Hours Loading	after two hours loading	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Heel, 20 Minutes After Off-loading	20 minutes after off-loading	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Skin Surface Temperature in °C Per Skin Area at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Skin thermometer based on the infrared technique (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure the skin surface temperature in °C.
Erythema Index in Arbitrary Units at the Sternum (Control- Area), at Baseline	Baseline	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Skin Surface Mean Roughness (Rz) in μm at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Skin Extensibility (Uf) in mm at the Sternum (Control- Area), at Baseline	Baseline	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Skin Extensibility (Uf) in mm at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Skin extensibility was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm diameter and expressed in terms of total extensibility of the skin in mm (Uf, mm).
Skin Surface Mean Roughness (Rz) in μm at the Sternum (Control- Area), at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany) device. It consists of a UV light camera and measures the skin surface profiles. Rz is the arithmetic average of different segment roughness values calculated with visioscan software. The median was calculated from the Rz values from the 15 participants for each Intervention Group.
Erythema Index in Arbitrary Units at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Erythema was measured with the Mexameter® MX 18 device by using specific wavelengths (the intensity of the reflected red (λ = 660 nm) and green (λ = 568 nm) lights) to measure the absorption capacity of the skin (specifically the content of hemoglobin in the skin). Lower values represent less redness.
Stratum Corneum Hydration (SCH) in Arbitrary Units at the Sternum (Control- Area), at Baseline	Baseline	Corneometer® CM 825 (Courage \& Khazaka electronic GmbH, Cologne, Germany) was used to measure SCH in arbitrary units (AU) (range 0-120 AU). Lower values represent reduced skin hydration in the upper skin layer.
Skin Surface Maximum Roughness (Rmax) in µm at the Sternum (Control- Area), at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Surface Maximum Roughness (Rmax) in µm at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Rmax (Maximum roughness) is the biggest roughness of the different segment roughness values.
Skin Elastic Function (Ur/Ue) at the Sternum (Control- Area), at Baseline	Baseline	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Elastic Recovery (Ur/Uf) at the Sternum (Control- Area), at Baseline	Baseline	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Elastic Recovery (Ur/Uf) at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	The elastic recovery (elastic recovery (Ur) / maximum extension (Uf)) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.
Epidermal Moisture Measurements Per Skin Area in Percentage (%) at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Epidermal moisture (measurement depth 0,5mm) was measured using MoistureMeterEpiD (Delfin Technologies Ltd.). The values are expressed in percentage of local tissue water (0 to 100 %).
Skin Surface Mean Roughness (Ra) in μm at the Sternum (Control- Area), at Baseline	Baseline	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Surface Mean Roughness (Ra) in μm at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	Skin roughness was measured using the Visioscan VC98 (Courage+Khazaka, Cologne, Germany). It consists of a UV light camera and measures the skin surface profiles. Ra is the arithmetical mean roughness calculated with visioscan software. The median was calculated from the Ra values from the 15 participants for each Intervention Group.
Skin Elastic Function (Ur/Ue) at the Sternum (Control- Area), After Two Hours Loading	after two hours loading	The elastic function (Ur/Ue) of the skin was measured using the Cutometer® MPA 580 and the corresponding software (Courage \& Khazaka Electronic GmbH, Cologne, Germany).The measurements were conducted whit a pressure of -450 mBar and a probe opening of 2 mm Diameter.